1. Field of the Invention
The present invention relates to machines and methods for harvesting food crops, and more particularly, to improved small-scale machines and related methods for separating larger volumes of vine-borne crops from their vines while effectively removing unwanted dirt, vegetation and debris, minimizing damage to the fruit itself, and promoting better sorting of fruit.
2. Description of the Prior Art
Vine-borne crops have traditionally been harvested and processed by hand. However, such manual harvesting and processing was often tedious, time-consuming and expensive. Various machines, such as the one disclosed in U.S. Pat. No. 6,033,305, have been developed over the years to automate part, or all, of this process. These machines are able to harvest vine-borne crops from the ground at much faster speeds than humans. However, these machines were often inefficient in other aspects of the harvesting process. Early harvesting machines severed entire plants and dropped them upon the ground, with the desired crops remaining affixed to the plants. Then, collection devices would retrieve the mixture of vegetation, dirt and debris for processing. Human sorters would then be required to sort through the mixture to separate the crops from the rest, and extract the former. The human sorters had to quickly process these mixtures to prevent a backlog. As a result, some suitable crops were lost because they were too far entangled within the plants, or simply overlooked by the human sorters.
Various devices have been developed over the years to improve the mechanized harvesting process, and to minimize the need for human sorters. For example, U.S. Pat. Nos. 4,257,218, 4,335,570, and 6,257,978 all disclose harvesting machines utilizing at least one form of agitating device (such as vibrating shaker heads or conveyor belts) to dislodge tomatoes from the vines. Several harvesting machines, such as those disclosed in U.S. Pat. Nos. 6,257,978 and 6,033,305, also utilize forced air pressure systems to further remove dirt and debris.
Unfortunately, larger is not always better. While wider and larger machines are generally capable of harvesting and processing a higher volume of vine-borne crops, many road and/or field situations make it impossible or impractical to use or bring these large machines in to perform the desired harvesting. Such machines are also more difficult to maneuver. Such limited maneuverability may require the machine operator to spend additional time repositioning the machines to process each row of crops, or cause the machines to inadvertently trample one or more rows. In addition, larger machines tend to weigh more, and the added weight not only affects maneuverability (e.g. turning), it also makes the larger, heavier machines unusable in moist or muddy fields where they tend to bog down. It is therefore desirable to provide a smaller scale machine that is capable of harvesting larger volumes of vine-borne crops.
In addition, the design of many existing large and small-scale machines may cause damage to the fruit by imparting numerous drops and/or turns during processing. Many machines require the fruit to drop a distance of several feet over the course of processing through the machine, and to make several turns during the process. Each drop and each turn provides another point where the fruit may be damaged, so it is desirable to minimize the number and/distance that the fruit drops through the machine, and to minimize the number of turns the fruit makes as it travels through the machine.
Effective separating and sorting of harvested fruit is also important. More efficient removal of dirt, vegetation, trash and debris as well as more accurate sorting of fruit is possible when the harvested materials are uniformly dispersed, and not bunched together. An unfortunate side effect of machines in which the fruit makes multiple turns is that the fruit and associated trash and debris tends to bunch together. Rather than the fruits being evenly spaced upon the conveyors (so that they may be easily examined and processed), these corners cause the fruits to become crowded as they are transported onto an intersecting conveyor potentially forming windrows, making them more difficult to inspect and sort. This bunching makes removal of the trash and debris more difficult, and once removed, the bunching of the harvested fruit makes sorting more difficult as well. Furthermore, each turn involves a drop from one conveyor to another, risking additional damage to the fruit, and requiring more maintenance and cleanup from breakage. Transverse turns also tend to increase the overall width and size of the harvester machine. All of these consequences make it even more desirable to minimize the number of turns the fruit makes as it travels through the machine.
Blowers for cleaning trash and debris out of the fruit stream have been used in existing machines. Air from the blower is typically directed between two conveyors into the fruit stream as the fruit makes a ninety degree turn at the rear of the machine. The trash and debris is blown far enough to clear the receiving conveyor and drop off to the ground. It is therefore desirable to provide a machine with a blower unit that does not require the fruit to be subjected to the problems associated with unnecessary turns.
Suction units have also been used in existing harvesting machines for pulling the trash off the fruit stream on each side of the harvester, with the fan positioned in the typical application directly above a pickup point as fruit moves from one conveyor to another. This is not feasible for use on a small scale machine because of vertical space limitations of fitting a sufficiently large enough fan without lengthening the machine further or raising the height and creating shipping problems. The additional single conveyor width compounds the problem. It is therefore desirable to provide an effective suction system that may be used in a small scale machine.
It is therefore desirable to provide a small-scale vine-borne crop harvesting machine capable of processing a large volume of crops that is usable in a wide variety of field situations where larger machines cannot be used. It is further desirable that the harvesting machine effectively process vine-borne crops with minimum potential damage to the fruit. It is further desirable that the machine provide a minimum number of drops and turns so that the fruit is less susceptible to damage, so that trash and debris may be more effectively removed, and so that the fruit itself may be more efficiently sorted.